PROS1 and COVID-19: One autopsy study reported IHC-detectable viral spike protein in lungs of 57% of COVID-19 fatalities (13/23) and concluded that “viral infection in areas of ongoing active injury contributes to persistent and temporally heterogeneous lung damage” [18], while another autopsy study used nucleocapsid protein immunohistochemistry and detected virus in only 7% (1/14) of COVID-19 decedents, and concluded that “direct viral tissue damage is a transient phenomenon that is generally not sustained throughout disease progression” [19].